I have the bog standard P20
Like the Pro, it gets higher DXO scores than the Samsung S9, Google Pixel 2 and Apple iPhone X. Likewise, as per this this review, Huawei's JPEG processing most certainly lags. The HDR mode in particular looks quite poor compared to my Nexus 5X. This is not a good phone camera for a dreary day. Playing to its strengths, however, which are good light and low light (e.g. indoors), it's looking very promising.
I'm not finding the iOS aping interface a problem at all. Nor does the notch bother me either way. There are use cases where face recognition doesn't work well for me. Something to do with how the phone detects movement, I think. Picking the phone up from a table or desk, the screen switches on and face recognition works pretty flawlessly. Taking the phone out of my pocket, OTOH, it often fails to activate.
Speed wise, the phone fast and slick, so no complaints there.